Motor-control device



May 21, 1929. c. c. PARRISH MOTOR CONTROL DEVICE Filed Dec. 15, 1926 3Sheets-Sheet bwentor: CFC/A C. Pa e/5H,

May 21, 1929. c. c. PARRISH MOTOR CONTROL DEVICE Filed Dec. 15, 1926 3Sheets-Sheet IIIIIIIIIIIIIIIII Inc/@7680 CFC/L C, 8469/6/1,

May 21, 1929. 5;. c. PARRISH 1,713,916,

MOTOR CONTROL DEVICE Filed Dec 15, 1926 3 Sheets-Sheet 5 iJNiTE-o sT T sPATENT OFFICE;

CECIL G. PARRISH, OF DONORA, PENNSYLVANIA.

moronconraOr. nnvron.

Application filed December 15, 1926. Serial No. 155,003.

This invention relates to motor control devices and more particularly toan automatic reversing and safety limit stop for use on cranes and otherlifting devices, and has for one of its objects the provision of acontrol switch adapted to prevent the over running of the hoistingelement of such devices. 1

Another object is to provide a control mechanism which will normallyremain in position to complete the field circuit to the motor beingcontrolled, in the direction of operation, and will when trippedautomatically short circuit-the armature with a series brake and aresistance unit to stop the motor.

A further object is to provide a-control mechanism of the classdescribed composed of a main switch unit and a short circuit unit, sothat the main switch unit may be located at any convenient place uponthe hoisting mechanism, while the relatively small short circuit unit ismounted in a position relatively close to the hoisting element.

A still further object is to provide a control mechanism of the class,dcscribed having the novel construction, combination, and

design of parts hereinafter described and illustrated in theaccompanying drawings. In the drawings v Figure 1 is a top plan of aswitch unit constructed in accordance with this invention, having thetop cover plate removed.

Figure 2 is a front side elevation thereof, with the front side plateremoved' Figure, 3 is an end elevation'taken on line III-J11 of Figure2.

Figure 4 is a rear side elevation. 7

Figure 5'is a top; plan of the short circuiti'ng unit used in connectionwith the switch of Figures 1 to 4 inclusiveQ Figure 6 is a sideelevation of the short circuiting unit.

Figure 7 is an end view of the short cir cuiting unit.

Figure 8 1s 'a general -w1r1ng diagram showing the switch unit and shortcircuiting unit wired up in connection with a motor series brake. andstandard reversing controller.

Referring more particularly to the drawings, the letter A designates theswitch case ing as a whole, which is adapted to house the switchmechanism. A contact arm 1 is arranged within the 'casing'A and carriesa solenoid plunger 2. A pair of top contact and 20.

nects the connectors 4 with a flexible con- I nector or lead 6.

A series operating coil 7 wound upon a spool 8 is mounted within thecasing A and adapted to cooperate with the solenoid plunger 2. The endsof the winding of the coil 7 terminate at taps 9 and 9, respectively,and the connector or lead 6 terminates at a tap 10. The taps 9, 9 and10, together with terminal taps 11 and 12, have a bus bar 13 whichconnects the taps 10, 11 and 12, and other taps 14, 15 and 16 aremounted on a terminal board B within the casing A. A pair of upper ortop stationary contact members 17 are mounted within the casing, A inposition to be engaged by the contact members 3 on the contact arm 1.The contact members 17 are provided with terminal taps 18 and 18. A pairof bottom or lower stationary contact members 19 are mounted within thecasing A in positionto be engaged by the lower contact members 3*. Thecontactmembers 19 are provided with taps 20 A spool is mounted withinthe casing A and is provided'with a resistance winding 21. The ends ofthe winding 21terminate at taps 22 and 22 A second resistance 23 ismounted below the casing A with the ends of the winding connected attaps 12 and 16 by wires 24 and 25, respectively. The resistance 23 hasapproximately ten times greater ohmic value than the resistance 21 andthe brake coil (to be described). I The short circuiting unit of Figures5, 6

and 7 has a casing or housing designated generally by the letter Cfwhichhouses the working parts of the unit. A lever arm 26 is pivotallysupported in the'casing C and carries a counterweight 27.

A-n insulating block 28 is niounted on the lever 26 and carries acontactor: 29, a flash contact 30 and a flexible connector 81. Mountedin the casing C is an insulator block 32 carrying contact bars 33 and34, and one end of the flexible connector 31 is attached to the contactbar 34. The outer end of the lever arm 26 is provided with a whichdepends a weight element36, L -In Figure 61 have shown the short cil'acuiting unit with the weight 36 in operative connection with thehoisting -ro pe 36? of a crane-hook 36 Refemngnow to Figure 8 in which-adiagram of the circuits made by the motor control or mechanism abovedescribed illustrated, the" numerai 37 designates the negative feed iineterminating at a tap 39. The numeral 38 designates the positive feedline, and the numeral 39. designates the controller which may he of anystandard design. 7 The field oi the motor to'he controlled is designatedby the numeralG, and the motor armature by the numeral 41,- while thebrake is designated by the'numeral Four 7 .conductor lines are shown asfollows-dine 43 with-terminal taps43 and 43 line d4 with terminal taps44 and 44 line 45 with terminal taps 45 and 45"; and line 46 withterminal taps 46 and .46..-

v Connecting the terminal tap' 9 on the switch unit with the motor field40, are wires 47 and 4Z withan'intermediate tap 47.

Connecting: the motor field with the conductor 46 are wires and 48 withan intermediatetap 48*,the wire'48? terminating at the tap 46*Einthewire 46. Connecting the terminal tap 9 with the conductor wire 43arewires 49 and 49? with an. intermediate tap 49, the wire 49terminating at thertap 43 the wire43. Connecting the tap 47] withthe'bar34 of the short circuiting unit anvil-e50, and a wire 51 connects thetap '49. with the 'contactor bar 33 of the short circuiting unit.

Thetaps 11 and '22 are cohnectedhy a wire '52 7 while the taps 16 and 44are con nected'i) :3 a wire 53. "The taps-'16 and 20? are fconn ectedbya wire '54, and the taps 20 and 22 are-connected by a. wire .55. The

taps 18 and 18 areconnected by a wire 56,

anda w-ire 55! connects the taps 18' and 14.

The taps 14 and 48 are connected by a wire 58. Aj :59 connects the termnal tap 15 with the series brake 2y nd a wire 60.,

connects the tap 15 to the tap 20. The motor ar-mature {ll-and theseries brahe are con nected'bj' a wire 61,-Vand a wire 62 connects themotor armature l and conductor .45,

' the wire 62 terminating at the tap 'in the wire 45. A wire 63 connectsthe tap 39* on the congiofler'iw with theftap 442611 the conductor j Awire64 connects a termi-' nal 39 on the controller .39 with the tap 45"mthe conductor 45. r A 65 con-' nects a tap 39" 'on'the controller 39with the tap flit-in the conductorefi. The positive hne 38 connected tothe conductor43 at controller 39 will he movedtothe proper po sition tomakea circuit through the positive line 38 to the tap 433?, conductor43110 tap 43?, wire 49150 the tap 49", and through the wire 51 to theconnection with the har 33 *in the short circuiting contactonothencethrough the contact 29 and flexible connector 31 to the bar 34 and wire50 to the tap 47 and wire l'f 'to the motor field'i); From .the motorheld 40 the circuit continues through the wire 48,-tap 48 and wire 48*to the tap 462-33161 conductor 46 to tap 46 46 fthe circuit is continued'tap45. From the tap-45 the circuit is continned through the wire 62 tothe motor armature 41, through the armature 41 3116.

wire 61 to the series brake e2, through the brake 42 to the wire 59 totap 15, thence through the wire 60' to the j tap 2Q, a'rni through thecontacts 19 and 3 connector 4 on one end'of the contact arm 1 to bus barv 5, and through the connector '45 on the other side of the contactarm-f1 to contacts 3"! and 19., thence out through the tap 20? and wire54 to the tap 16;. -From thetap-lfi the oil'- cuit is continued throughthengvire 53.150 the tap 44", conductor 44 to tap 44 wire 63 to tap 39",and through the controller 39 to the ,tap 39, and thence to the minus ornega tive line 37 completing the circuit. 7

When th load or lifting element to a. predetermined height which isdeter mined by the position ot-the weighto36, a

lifting arm ID on the lifting element D engage and lift the weight-36.The or the weight-36 permit: the counter-j.

weight 27 on thellever arm 261:0 re the lever arm and break the contacthetwe is raised the contactor '29 and the bar 33, therehy'hreak ing thenormal operating circuit described V 1 v ahove,-and reestablish acircuit as follows- From the tap 49 the circuit isnnade a through thewire'49 to a tap 9, then throughthe series-operating coil 7, so as toenergize V the coil lg-and attract the plunger 2; .When the plunger 2 isattracted by; the coil? the plunger and contact arm 1 will move upwardlyand disengagei contacts 3% and 19, and engage contacts 3 and 17, therebycutting reslstance coil 23 into the motor circuit,

and also connecting" resistance coil 21- and brake 42-111 series acrossthe motor armature lis'oastoreestablisha'circuitasiollows+ to the top43', thence through'the-wire .49

From the tap 9 the continued through the '4j 47" the-motor 7 F rom theplus or positive line 38 (if-the tap 43, throu'gh the conductor or wire43 to the tap 4:9, 'then'through the wire 49 to thetap 9" on the bar B,and through the p I operating coilv 7 to the tap!) on the bar B; that aloadis tobe raised by field 40 and wire 48 to thetap 48 thence throughthe wires 58 and 57 to the tap 18,

and through the contacts 17 and 3 and con- .nector bar 4 to the bus bar5.

- Y25 and to tap 16. From tap 16 the circuit continues through the wire53 to tap 44 on the conductor 44 to tap 44, and thence through wire 63to the tap 39 on the controller 39 and through the controller 39 to thetap 39 and thence outthrough the minusor negative line 37 completing thecircuit. Simultaneously with the above circuit there also will be alocal dynamic braking circuit established from the terminal tap 48through the wire 48 to the tap 46 and through the conductor 46 to thetap 46 then through the Wire 65' to the tap 39 on the controller 39, andthrough the controller to the tap 39. From the tap 39 the circuitcontinues through the wire 64' to the tap and through the conductorf45and tap 45 to the wire 62, thence to the motor arma ture 41, throughthemotor armature 41 to the Wire 61 to the series brake 42, and thencethrough the wires 59 and 60 to the tap 20. From the tap 20'the circuitis completed through the wire 55, resistance coil 21 and wire 52 to thetap -11 on the bus bar 13, and-through bus bar 13 to the tap 10, thusdissipating the counter E. M. F. from the motor armature 41 in the coil21 and brake 42, thereby permitting the brake 42 to be deenergized andapplied when the counter E. M. F. has been dissipated.

Duetothe fact that'the resistance 23 has approximately ten times greaterohmicvalue than the resistance 21'and the brake coil,

. the current will follow the path of least resistance, during the loadholding position of the apparatus, so that the major portion of thecurrent will flow through wire 57, and out through the motor field 40,and operating coil 7 back to line, and only a negligible current leak ifany will flow through the the wire 61 to the series armature, brake, andcoil 7. This leak of current will not be sufficient to operate or aflectthe elements in its path.

When'the lifting element D is to be lowered, the controller 39 willbereversed so as to connect the terminal taps 39 to 39 and 39 to 39, asindicated in dotted lines on Figure 8. The lowering circuit will thus beestablished fromthe minus'or negative line 37 to the tap'39, through thecontroller 39to tap 39, then through the 'Wire 64 to the tap 45 and thenthrough the conductor or wire 45 to the tap 45. From the tap 45? thecircuit is continued through the wire 62 to the motorarmature 41,through brake 42 and through the wires 59 and 60' to the tap 20,

then through the wire 55 to and through the resistance coil 21. From thecoil 21 the circuit continues through the wire 52 to the terminal tap 11on the bus bar 13 and through the bus bar 13.to the tap 10, thence tothe flexible connector 6 to the bus bar 5 on the contactor bar 1, andfrom the bus bar 5 through the connector 4 to the contact 3, and throughthe contact 17 to the tap 18 and wires 57 and 58 to the tap 48.

From the tap 48 the circuit continues through the wire 48 to the motorfield 40 r and through the wires 47 and 47 to the coil 7, through thecoil 7 and wires 49 and 49 to the tap 43 on the conductor or wire 43 t0the tap 43 and out the plus or positive line 38 completing the circuit.

As soon as the load has been lowered a suflicient distance to allow theweight 36 to hang free of the lifting element or shelf 50, the weightwill rock the lever 26 against the pull of the counterweight 27 so as toengage the contact 29 and the bar 33 in the short circuiting unit. Theengagement of the contactor 29 and bar will short circuit the coil 7 soas to cause said coil to become deenergized and permit the contact 1 todrop by gravity and reestablish the lowering circuit as follows- Fromthe minus or negative line 37 through-the controller 39 and wire 64 tothetap 45 in the Wire 45 to the tap 45, thence through the Wire 62 tothe motor armature 41, and through the armature 41 and Wire 61 to theseries brake 42. From the brake 42 63 to the controller 39. The circuitis then continued through the controller 39 to the wire 65 and throughthe wire 65 to the .tap 46 on the conductor 46, then to the tap 46 andthrough the wires 48 and 48 to the motor field 40. The circuit is thencontinued through the motor field 40 and wire 47 to the tap 47, thencethrough the wire 50 to the connection at 34 in the short circuiting unitC, and through the connector 31 ,to the contacts 29 and 33. From thecontact 33 the circuit continues through the wire 51 to the tap 49 andthen through the wire 49 to the tap 43 'on the conductor or Wire 43 andto the tap 43 to the plus or positive line 38 completing the normallowering circuit.

VVhileI have shown and described a spe cific embodiment of my invention,it Will be understood that I do not wish to be limited to the detailsthereof, since various combinations maybe readily madelby those skilledin the electrical art without departing from the scopeof my invention asdefined'in the appended claims, 1

"I claim: 7

1. Theeombination with a series. motor having an armature, and a field,and a series brake, o control' mechanism for said motor. ]IlCll1(l l1lgan automatic switch "havin an 7 fl'operating position and a brakingpos1tion,"

a series solenoid for actuating the switch to the latter position, amechanical switch, said so enoid being in series with said field and inshunt with saidmechanical switch, and said automatic switch inbrekinposition being adapted to establish a local ynamic braking sal circuitthrough said armature and r e.-

-2. An apparatus for controlling a series motor, comprising a seriesbrake, an auto matic switch and a mechanical switch, said automaticswitch having a normal operating 7 position and a braking .ppsition,said mechanical switch havingan open position and a circuit closing postion, series electro-magnetic means for moving the automatlc switch 'tobraking position, said electro-magnetic- 7 means being 1n series withthe motor and in shunt with the mechanical switch, and said automaticswitch in braking osition being adapted to establish alocal ynamic-brak-. circuit through the armature and brake by which'dynamicbrakingis effected;

'mechanical switch having an open switch, and

being adaptul to establish, aflocaldynamic braking circuit throughsaidmotor 3. The combination with an electrically operated crane hoisthaving a lifting element and including ,a series motor having anarmature and a field, and a series brake,

.of, control mechanism therefor including an automatic switch and amechanical switch, said automatic switch having a normal operatingposition and'a braking position,said position and a circuit closingposition, a- 8813183616? tro-magnetic means for moving said automaticswitch into braking. osition, said elec- V tro-magnetic means being inseries with'said mdtor-field and in shunt with said mechan- "icalswitch, means operable b said li mechani element 'for operating 'salautomatic switch in brakingposition which dynamic braking is efiected.

4. The combination with an electrically armaturelandsaid so as brakethrough operated-crane hoist having adiiting ele-' ment, andincludingaseries motorhaving an armature and a field, a. serles'brake,and

'two resistance units, ofia control mechaincluding an automatic switchand a. mechanical switch, said automatic switch having anormal'operating-position and a switch in braking positionbeirggdaldapted to establish a. local dynamic b through the armature,brake, and one of said resistance units, said brake and last named.resistance unit being adapted to dissipate the energy -developed by thecounter. 7

M., F. of s'aiddynamic braking circuit,

g re

and said automatic switch :in braking position also being adapted to putthe other of said resistance units in series with said motor field soasto. govern the excitation of said field and thereby govern the counterE. M. F. generated by said motor.

"5: The combination with a series motor having an armature and a field,a series brake,

and a resistance unit, of a control mechanism "including an automaticswitch having a nor- 7 mal operating position and a brake-position,

a series electro-magnetic means for operating the automatic switch tobraking posia mechanical switch, said electron-mag with said field tion,netic means being in series "and in shunt with said mechanical switch;

and the automatic switch in braking position being adapted to shunt thearmature circuit of the motor with said brake and saidresistanceelement.

operated hoisting crane, said mbtor' having an armature and a field,

' -6. The combination seems motor a series brake,

and a lifting element adapted to be operated by saidmotor, of a controlmechanism including an automatic switchand a mechanical switch, saidautomatic switch having a normal operating position and a brakingposition, said mechanical-switch having an open "a serieselectro-magnetic ineans for. operating said automatic switch to brakingpos iposition and a circuit closing position,

tion, said electro-magnetic'means, being n v series-with-the field ofsaid motor and in shlmt with said mechanical switch, and the "automaticswitch in braking position being adapted to. shunt the normal armaturecir- 5 cuit of said motor through ,a resistance unit 'so that the motorma ,act as a generator and create a-counter E. ergy dissipated throughsaid resistance unit and said brake. w

In witness whereof,-

have hereunto signedmynamaseem cl me a F. which has its en-

